Keep track of red flags for prescription drug misuse in one place in the patient’s file: That’s how to prevent signs of a pattern of problematic behavior from slipping through the cracks. One major red flag is a history of substance abuse.
"It’s super important to at least ask about alcohol or substance abuse and document it in the chart, recognizing that you may not get an honest answer," Dr. Gaster advised.
"Anyone with a history of substance abuse should be treated with opiates for bad somatic pain only with extreme caution. The risk of prescription drug abuse in someone who has a history of substance abuse is dramatically higher. This is a completely different class of prescribing. It’s hard to say such people should never be on chronic opiates, but a much, much higher level of caution is required," he said.
As for patients with an ongoing substance abuse problem who also have obvious severe somatic pain, on balance the risk of harm in prescribing chronic opiates exceeds the potential benefit.
"These are terrible situations. I’d say primary care doctors shouldn’t be doing this at all. Such patients should be offered a referral for substance abuse treatment," he said.
Hepatitis C infection is another major red flag because it’s an important epidemiologic indicator of past illicit drug use.
Use a urine toxicology screen: An "absolutely essential part of the tool kit" because it’s the only source of hard data regarding whether a patient is abusing or diverting prescription drugs. Do it randomly but fairly frequently, and let the patient know that any time a urine screen is ordered, leaving the clinic without providing a urine sample that day will be considered tantamount to a positive test and will result in discontinuation of opiate therapy.
"If you were to pick out the one thing on a urine toxicology screen that’s most informative, I’d say it’s a positive result for cocaine. Cocaine use has a very, very high correlation with prescription drug abuse, and there are virtually no false-positive results for cocaine," the internist said.
In contrast, false-positive results for amphetamines are a real problem. The ELISA assay for amphetamines turns out to have cross-reactivity with at least 20 prescription drugs, including bupropion, phenergan, and legitimate medications for attention-deficit/hyperactivity disorder. Having the lab run a gas chromatography test will differentiate prescription stimulant medications from illicit street amphetamines.
Another key point about urine toxicology screens is they don’t reliably detect synthetic opiates such as fentanyl, or semisynthetic opiates such as oxycodone.
"Patients taking oxycodone may very well have a negative toxicology result, so you always need to make sure to order a separate oxycodone assay as part of your toxicology screen," he advised.
Also, before bringing up the need for a urine screen that very day, be sure to ask when the patient took his last opiate pill. That will be most helpful in interpreting a negative result.
For patients on dialysis who are anuric, use serum drug testing.
Utilize the statewide prescription monitoring system: It’s an essential tool for detection of patients who are sneaking around and obtaining opiate prescriptions from multiple physicians and then selling them.
"The giant street market for prescription opiates is, to some extent, happening from pharmacies and warehouses being robbed, but the vast majority of those pills are coming from doctors’ offices," Dr. Gaster noted.
Stop chronic opiates in response to red flags: This is one of the most difficult and emotion-charged interactions that occur between physicians and patients. "I rank it right up there with having to deliver a cancer diagnosis," Dr. Gaster said.
Patients seldom take this news well, so it’s a good idea to practice this straightforward phrasing beforehand: "In my medical opinion, this type of pain medication is simply not safe for you and I cannot prescribe it for you anymore."
To avoid legal and ethical problems, it’s important to emphasize that patients are not being fired or abandoned. Explain that you’re willing to continue as the patient’s physician, but not in prescribing opiates, he said.
Dr. Gaster reported having no financial conflicts.